Sewing machine



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July 13,1926. 1,592,434

D. BELCHER SEWING MACHINE yOriginal Filed Jan. 29. 1921 5 Sheets-Sheet 2July 13 1926.

D. BELCHER SEWING MACHINE Original Filed Jan. 29. 1921 5 Sheets-Shogi. 3

July 13 1926.

D. BELCHER SEWING MACHINE origina Filed Jan. 29. 1921 5 Sheets-Sheet 4July 13 1926. 1,592,434

D. BELCHER SEWING MACHINE Original Filed Jan. 29, 1921 5 Sheets-Sheet 5Patented July 13, 1926.

UNITED STATES PATENT OFFICE.-

DANIEL BBLCHER, OF MINNEAPOLIS, MINNESOTA, ASSIGNOR T BEMIS BRO. BAGOOM- PANY, OF ST. LOUIS, MISSOURI, A CORPORATION 0F MISSOURI. i

` SEWING MACHINE. 'v T Original application illed January 29, 1921,Serial No. 440,927. Divided and this application illed January 14, 1924.

This invention relates toimprovements in sewing machines and has for itsprimary object a machine which will make a strong close lying stitch andat the same time save a considerable amount of thread. v

A. further obj-ect' is to construct a sewing machine which is providedwith a means to prevent backlash or formation of a double loop of needlethread at the needle point. lVhere this double loop forms it becomesentangled with the looper and the needle .thread is torn thereby causinga rejection of many sewed articles. By preventing the formation of adouble loop this trouble is eliminated. f

A still further object is to construct a sewing machine for formingthread saving stitches which is provided with aplurality of devices suchas an intermittent threadlock for the needle thread, a slack take-up forthe needle thread, and a slack pull-up and releasing device for thelooper thread by means of which a stitch is formed in whic the looperthread lies close to the fabric and practically no needle thread isexposed on -the looper side of the fabric. The entire stitch on thelooper side being extremely smooth and lying close to the fabric so thatthere will be substantially no give to the seam and the various layersof fabric rmly united together.

This application is a division of the application filed by me January29, 1921, Serial o. 440,927 for improvements in the method of forminstitches.

Fig. 1 is a front elevation of a portion of a sewing machine showing myimprovements thereon; e

Fig. 2 isa rea-r elevation of the same;

Fig. 31s a top lan view of the same;

Fig. 4 is an end) elevation of the same;

Fig. 5 is an enlarged plan view of the looper thread take-up cam;

Fig. 6 is a side elevation of the same;

Fig. 7 is a top plan view of the supporty glade use of for the pantension on the needle T ar; A ,i

Fig. 8 isan enlarged vertical cross section of the intermittent threadlock;

e Fig. 9 is, an enlarged end view of the stud onwhich the thread lockoperates;

Figi y10 isan enlarged 'face view of the Serial No. 685,976.

tafiionary cam made use of in the thread Fig. 11 is an enlarged faceview of the movable cam made use of in the needle thread lock; l

Fig. l2 is an enlarged vertical section of the rocking mechanismemployed for operating the looper;

Figs. 13, 14, 15, 16, 17 and 1s are da! grammatic sectional views of thelooper threadtake-up cam showing the same in various positions duringits operation;

- Fig. 19 is an enlarged plan view of the looper side 'of the stitchwith a portion of the needle thread broken away and in section; and v-Fig. 20 is a vertical section taken through the fabric adjacent thestitch and showing the position'of the needle and looper threads.

In the construction of my device I employ a machine-head comprising abase having an integrally formed arm 26. The arm 26 has an integrallyformed bearing '27 through which a shaft 28 extends.- The base 25 isprovided adjacent its forward end with an integrali formed upwardlyprojecting lug 29 in which the shaft 28y is also journaled or supported.

A The shaft 28 extends through the arm 26 and has located upon itsproject-ing end a sheave wheel 30 and between the sheave wheel 30 andarm 26 is located an eccentric 31. The eccentric 31 may be formedintegral with the wheel 30, it may be separate and securedeither on theshaft 28 or to the sheave wheel 30, or it may be formed integral withthe shaft. This construction of cam resting entirely with themanufacturer as either type of cam will not affect the operationof mydevice at all.

Surrounding the eccentric 31 is an eccentric strap 32 which has securedthereto one end of a connecting rod 33, the opposite end of theconnectin `rod is secured in a socket 34 which has a Iiearing 35 formedintegral with its upper end. Mounted in the bearing 35 is one portion ofa balljoint 36, the other portion of this joint is firmly secured to theprojection 37 formed integral with the needie bar lever 38. The needlebar lever 38 is ivtally secured intermediate its ends to t e arm 26 atthe point indicated by the numeral '39. Secured xto the end/10 of theneedle bar lever are links 41, which links are in turn secured to a lug42. This lug is in turn firmly secured to the needle bar 43 so that uponrocking of the lever 38 the needle bar is reciprocated up and down.Formed integral'with the arm 26 are bearings 44 through which the needlebar extends and which serve as guides for the bar.

The needle bar has its lowerend tapered and split, this tapered splitend is provided with screw threads 45 over which theI nut 46 is adaptedto be secured. The lower portion of the needle bar is also provided withav bore for the reception of the upper end of the needle 47 and when theneedle is placed in this bore and the nut 46 tightened the lower end ofthe needle bar will be pressed together thus securely holding the needle47 in place.

The end 48 of the needle bar lever 38 is provided with a stud 49 towhich is secured a bearing 50 which has secured thereto one end of theconnecting rod 51. The opposite end of this rod is secured to a similarbearing 52, which bearing is secured to the stud or pivot 53. The stud53 is in turn secured to the looper 54.

Formed integral with the arm 26 is a projection 55 through which extendsa screw threaded rod or bar 57, and on this bar are loosely mounted thepan tensions 58 and 59. The tension 58 being for the needle thread andthe tension 59 for the looper thread. These tensions are regulated bymeans of a thumb nut 60 and coil spring 61 and when once regulated forthe particular kind of work, remain constant.

Extending through the projection 55 is a bar 62 which is providedadjacent each end with openings, these openings act as guides for theneedle and looper threads, keeping them in alinement with theirrespective tensions. v

Secured to the needle bar lever 38 is a bifurcated arm 63 which haslocated in its bifurcation the arm 64 of the movable cam member 65. Thecam member is provided with inclined faces 66 which contact with theinclined faces 67 of the stationary cam member 68. The movable cammember 65 is provided with a circular opening 69 which is adapted to fitover the cylindrical portion 70 of the stud 71. The stud 7l is securedin a bracket 72 which is firmly attached to the arm 26. The Stationarycam 68 is provided with a square opening 73 which is adapted to fit overthe square portion 74 of the stud 71 and thus prevent the cam memberfrom turning. The stud 71 is secured in the bracket by means of the nut75 and screw 76. -My purpose of thus securing the stud is that the nut75 will prevent any longitudinal movement of the stud, while the screw76 will prevent any turning. The prevention of turning of the Stud 7l isvery essential as the turning of the stud will cause a variation in thedegree of tightness between the pans 77 and 78 which would cause them toexert more or less pressure on the needlethread by the operation of theneedle bar lever. The tension exerted by the pans 77 and 78 isintermittent but is made adjustable so as to accommodate diiferent sizesor thicknesses of thread and also to permit adjustment for various kindsof work. The

regulation of the tightness between the pans 77 and 78 is regulated inthe following manner z-If the stud is turned so that the stationary cammember carried by the square portion thereof revolvesl toward the needlebar or counter-clockwise, the oscillation of the movable member willcause it to ride up on the cam surfaces of the stationary member lto agreater degree and consequently cause more movement of the pans 77 and78 than if the stud were revolved in the opposite direction. In otherwords, turning the stud counter-clockwise the highest point of thestationary and movable cams are more widely separated than if the studwere revolved clockwise. The riding of the cam surfaces upon veach-other and the consequent binding of the pans 77 and 78 on the needlethread 7 9 is occasioned by the reciprocating movement of the bifurcated`bar 63 due to the movement of the needle bar lever. This reciprocatingmovement of the bar 63 is in turn communicated to the movable cam 65,which due to the fact that the stationary cam 68 cannot rotate willcause the cam faces to ride up on each other and force the pans 77 and78 towards each other thus binding the needle thread between the twopans. Secured to the arm 26 is a guide 80, the purpose of which is toassist in guiding the thread from the pan tension 58 between the pans 77and 78. The needle bar lever is also provided with la loop 81, thepurpose of which is to assist in pulling off suflicient needle Vthreadfor the next stitch and also to assist as a 'pull-up for the needlethread during a portion of the stitch formation. i

Near the upper end of the needle bar 43 is a loop 82 through which theneedle thread 79 passes.. After passing through the loop 82 the threadis then passed through the pan tension 83 which is secured to the needlebar 43. The stud 84 on which the pans 85 aa'e secured is provided with acircular o ening 86, this opening has a slot 87 exten ing to the outersurface of the stud 84 so that the thread can be readily insertedtherein without the necessity of spreading the pans apart and pushingthe end of the needle thread through the opening 86. After the threadhas been thus inserted the openin acts as a guide for the needle threadan holds it between the disks of the pan tension. After bein threadedthrough this pan tension, whc remains constant atv al1 times, the lowerend of the needle thread is then insertedV through the eye of the needle47.

Secured to the upper portion of the arm 26 and preferably extending onboth sides of the needle bar 43 is a vertically adjustable member 88.Thismember co-acts with the loop 81 carried by the needle bar to act asa pull-up on that strand of needle thread adj acent the Vintermittenttension. vThe vertical adjustment of the member 88 regulates thestarting point of the pull-up on the needle thread and consequently theamount of such pull-up. And in order to prevent the needle thread fromslipping olf of the member 88 an upturned ortion 89 is provided. Theadjust-ment o plished by loosening the set screw 140 and raising orlowering the post 141. The drawing up is accomplished in the followingmanner-As the loop 82 passes downward past the extending portion of themember 88, the extending portion of the member 88 prevents the needlethread from traveling downward with the movement of the needle bar anddue to the fact .that at this period the needle thread has -been clampedby the intermittent thread lock no more thread can be fed through theneedle and consequently a pulling up on the Strand of thread adjacentthe intermittent lock will result. This operation will be explained indetail later.

On the end of the shaft 28 which projects through the bearing or support29 is secured a disk 91 which is provided with a diainetricallyextending slot 92 which is T-shaped in cross sectionand in which ismounted the head of a bolt 93. On the shank of this bolt is secured oneend of a link 94, its opposite end being secured in the arm 95 of therocking frame 96. The rocking frame is provided on its ylower end withbosses 97 through which a shaft 98 eX- tends, the ends of which aremounted in bearings 99 formed integral with the base 25. The upperportion of the rocking frame is provided with bearings- 100 whichsupport a shaft ,101. The shaft 101 is secured in the bearings 100against longitudinal movement and in turn supports the arm 102 to whichthe toothed feeder 103 is secured.

It will be noted from Fig. 4 that the link 94 is eccentrically andadjustably mounted in the disk 91. This eccentric mounting imparts arocking motion to the frame 96, which rocking motion is in turnconverted into a reciprocating motion for the feeder 103.

The T-shaped slot prevents the head of the bolt 93 from coming out ofthe disk. The head of this bolt is provided with a screw threaded borewhich receives the thread portion of a screw 104. The purpose of thisscrew 'is to vary the eccentricit'y of the member 88 is accom' the link94 and consequently the reciprocating movement of the feeder 103 whichvaries the amount of fabric fed or rather the rate of feed andconsequently the length of the stitch so that either a coarse or finestitch can be attained.

Formed integral with the base 25 are proi ing as a pivot for the looper54. Secured on the shaft 107 and located between the lugs and 106 is abifurcated member or fork 111, its bifurcation straddling the cam 112which is secured to the shaft 28 and rotates therewith. This cam andbifurcated member impart an oscillating motion to the looper 54. Thatis, cause the loopcr to rock laterally bringing the looper first to thefront and then to the rear of the needle as it penetrates the fabricbeing sewed.

Formed integral with the base 25 is an upwardly projecting casting 113to which is pivotally secured a U-shaped thread `uide 114, which guideis also capable of adjustment up and down by means of the screw 138.This screw iscapable of being raised and lowered and supports one arm ofthe thread guide 114. The arm being held in constant contact with thescrew head by means of the spring 142 which bears against the outwardlybent portion 143 of the U- shaped guide 114. This adjustment is for thepurpose of regulating the amount of slack taken up and also the time atwhich the looper thread 115 contacts with the loopcr thread take-up cam.The thread guide 114 is provided adjacent its open endv with openingsthrough which the loopcr thread 115 is passed. The thread guide 114 isfor the purpose of holding the looper thread over the looper threadtake-up cam 116 which is-mounted on the shaft 28 and rotates therewith.The looper thread cam is provided with a central groove 117 into whichthe thread remover 118 extends.

jection 113. Secured to the projection 113 and extending above thethread remover 118 is a hook 119, the purpose of which is to retain thethread during a certain portion of the movement of the cam 116. The cam116 is provided with faces 120, 121, 122, 123. 124 and 125, the purposeof these faces will be explained in detail later.

The projections or lugs 29 and 106 are provided on their-upper ends withplane surfaces 126 and in these surfaces are formed The thread removeris also securedto the proscrew threaded openings for the purpose ofsecuring a plate (not shown in the drawings) thereto, which plate isadapted to act as ay rest for the work.

The base 25 is also provided with a projecting lug 127 to which a cover(not shown) is hingedly secured. The purpose of this cover is to enclosethe mechanism which operates the rocker frame 95 but still allow readyaccess thereto for adjusting purposes.

Mounted in the arm 26 is a presser foot bar 128 to which the presserfoot 129 is se-v cured. The presser bar 128 has secured thereto aprojecting lug 130 on which one end of a spring 131 rests, the oppositeend of the spring is secured to the projecting lug 55. The desiredpressure of the presser foot is imparted to the spring by means of theadjusting screw 132. The presser foot 129 and bar 128 are raised bymeans of the eccentric-lever 133. The purpose of raising the presserfoot is to permit the desired ad justment of the various tensions andfor threading the looper as the machine can then be easily turned byhand so that the various operating parts will assume their necessarypositions for these purposes. This raising of the presser foot is alsonecessary for the insertion of new work. The raising of the presser footis accomplished by raising the eccentric lever 133 which contacts withthe stud 134 which is carried by the presser foot bar 128.

In order to keep the bar 128 and presser foot 129 from turning I makeuse of a sliding shaft 135 which is connected to the bar 128 by means ofthe stud 136. The shaft 135 is spaced apart from the bar 128 andprevents through its connection any turning of the presser foot whenemploying the eccentric lever 133 to raise the foot and also holding thepresser foot in proper alinement while the work is passing through themachine.

Secured to the base 25 is a guide 137, this guide is for the purpose ofhaving the looper thread passed therethrough from the pan tension 59 sothat it will be properly guided to the thread guide 114 without comingin contact with any of the working parts otl the looper mechanism.

The operation of my device is as follows- The machine is first threadedin the following manner-the needle thread 79 is first passed through theopening in the bar 62, this opening being the one located to the frontof the machine. The thread is then passed down underneath the bar 57 andthen between the pans 58 and the pan tension, from there the threadpasses through the thread guide 80. The thread is then passed betweenthe pans 77 andV 78 and through the loop 81 after which it is passedthrough the loop 82 carried by the needle bar, thence downward throughthe pan tension 830erried by the needle bar, and lastly threaded throughthe eye of the needle.

The looper thread 115 is passed through the opening in the bar 62 to therear of the machine, from there is inserted in the pan tension 59, afterwhich it passes downward and is inserted through the guide 137. It thenis passed forward and passes through the openings formed in the threadguide 114, after which it is passed or threaded through the looper 54;.

The machine is preferably driven by means of a belt which is passedaround the sheave wheel 30 and which is driven from any suitable sourceof power, such as a line vfoot lowered, after which the machine isoperated for a few stitches, the stitches are new examined and the pantensions and intermittent tension so regulated as to give the properdegree of tightness to the threads and stitch. After these adjustmentshave been made the device is ready for its operation.

The various sequential steps will be described commencing with theneedle bar raised to its highest point, after which the first step willbe the movement of the needle bar lever in such a manner as to carry theneedle bar and needle downward with it so as to penetrate the materialbeing sewed. This operation carries the needle thread through the fabricin the form of a loop and at the same time commences to operate theintermittent lock. This lock gradually tightens on to the thread untilthe lowest point of travel on the needle bar lever has been reached, andduring the latter portion of this tightening of the intermittent orthread lock, the loop carried by the needle bar passes by the needlethread pull-up 88 which imparts a retrograde movement -to that strand ofneedle thread between the intermittent tension and the needle point.This upwardpull draws up the previously formed stitch and seats ittightly. 1

The various movements of the looper thread are as follows--Just as theneedle is ready to descend, the talre-up cam is in the positionillustrated in Fig. 14 and as the needle commences to descend the looperthread lying on the face 125 of the cam 117, this thread is carriedupward by the face 125 as illustrated in Fig. 14 and isforced along thisface by means of the thread remover 118 until it rides on the face 120.The looper thread slides along the face 120 until it comes in contactwith the hook 119 Where it relnains until the face 120 is clear of thehook. The looper thread is then permitted to pass the hook 119 and falldown on the face 121 along which it travels until it comes to the face122 which picks it up and carries it upward until it again contacts withthe thread remover 118. The additional projection formed by the camfaces 122 and 123 then exerts an additional pullup and thereby places atension on the looper thread whichv ldraws it tightly against theunderside of the fabric just at the time that the needle thread is beingacted on by the needle thread pull-up. The thread then slides along theface123 but is held by the hook 119 until the face 124 assumes theposition shown `in Fig. 18.l after which it will slide under the hook119 and come to rest a ain on the face 125 after which the operation isrepeated.

The operation of the machine or in other words the formation of thestitch is as follows-Just as the needle is ready to 4descend the looperand cam are in the positions shown in Figs. 3 and 14, after the needlecommences todescend the looper commences to move forward and by the timethe needle is ready to rise the looper passes through the loop of needlethread carrying with 1t a loop of loo r thread. At this point the looperis to thi rear of the needle. Phe needle next is withdrawn from thefabric and the looper swings forward and at the same time moves backwardthus releasing the loop of needle thread which it has previously caughtup. The needle and needle thread now descend through a loop of looperthread which has been caught by the previous loop of needle thread andas the needle continues to descend the previ.- ous loop of needlethread. is drawn up taut against the underside of the fabric. Just atthe point of drawing up of the needle thread the looper has been pulledback and oscillated so that it isY to the rear of the needle thread andwhen the needle commences to be withdrawn again thus forniing a loop ofneedle thread below the fabric the looper and looper thread again enterthis newly formed loop, after which the previous operation is repeated.

It is of course to be understood that as soon as the needle has beenraised out of the material being sewed, the feeding mechanism causes thefeeder plate to grip the Work and carry it forward under the presserfoot a suliicient distance to form the stitch.

The saving of thread is illustrated in the following example, the sizesof threads employed being those commonly used for bag sewing- The threadused is 5 ply for the needle thread and 3 ply for the looper thread andthe basis of measurement o thread being a one ply thread so that onefoot of needle thread will be equivalent to 5 feet of one ply thread,and one foot of looper thread equivalent ,to 3 feet of one ply thread. pIn the old stitch made by machines as used at `presentfor bag sewingthere are approximately 3.5 of 5 ply thread used for every foot ofsewing. This is equivalent to 17.5 feet of one ply thread, whileapproximately 1.5 feet of 3 ply thread is used for the same amount ofsewing,-tliis is the equivalent of 4.5 feet of oneply thread, making inall a total of 22 feet of one ply thread.

In the stitch as made by my improved method and attachments I useapproximately 1.5 feet of 5 ply or 7.5 feet of one ply thread in everyfoot of sewing, while approximately 3.5 feet of 3 ply thread are used inevery foot, or 10.5 feet of one ply thread. This makes a total of 18feet of one ply thread used by my device in sewing one foot of fabric,as against 22 feet of one ply thread in the old device. This means asaving of 4 feet of one ply thread in every foot of sewing, which willrun into a considerable amount in the course of a day when it is figuredthat each machine turns (ut several thousand completed articles a Itwill be noted from Figs. 19 and 20 that one strand of looper threadpasses around the entire loop of needle thread projecting below thefabric, one strand of looper thread passes through the loop of needlethread,

and one strand of looper thread is bent around one of the strands ofneedle thread. The last two mentioned strands f looper thread beingbelow the first mentioned strand of looper thread thus holding ittightly against the fabric. This makes a total of three strands oflooper thread between adjacent loops of needle thread and as illustiatedin Fig. 20 a portion of the looper thread is partially imbedded in thefabric.

The distance to which the looper thread is imbedded depending on thekind of material and weave used for the .bags sewed.

It will also be noted that two strands of looper thread lie parallel toeach other so that each loop of needle thread embraces two strands oflooper thread. This has a tendency to spread out the loop of needlethread and thus make a stronger stitch, due tothe fact that the needlethread loop is spread out over two strands of looper thread which lieside by side. It has been found by actual test that the looper threadacts as a knife and cuts the needle thread when the saine is pulled up,so by having two strands of looper thread lying side by side and theloop of needle thread passing over both of these strands the cuttingtendency of the looper thread is considerably reduced because instead ofonly a round surface bearing against the needle thread loop, a widebearing surface is obtained and therefore the cutting tendency greatlyreduced.

During the operation of my device the pan tension carried by the needlebar holds the needle thread taut between the eye of the needle and thetension. My purpose in placing this pan tension on the needlebar isbecause I have found that without tlns tension the needle thread will attimes become slack and hang below the point of the needle so as to forma double loop. The needle 1n descending will pass through this loop ofslack and form an additional loop on the looper side of the fabric whichthe looper Will cut when entering the loop below the fabric and it istherefore impossible to make a continuous stitch. In other words, anarticle sewed when this happens instead of having a continuous stitchwill be held. together by a number of short sewed port1ons with spacesin between them which are not sewed due to the fact that the needlethread has been cut by the looper. This makes 1t necessary to reject thework and if the material is to be saved, the entire stitching will haveto be ripped and picked out and the entire work resewed.

It'will be observed from the foregoing dev scription that the threadlock, the loop on the needle bar lever and the loop on the needle bar,the tension on the needle bar, the vertically adjustable member carriedby the arm 26 and the looper thread take-up cam co-act and are necessaryin forming the stitch illustrated and described. The thread lockoperates intermittently to increase the tension on the thread, but doesnot lock the thread entirely against movement. This is necessary to seatthe loop of needle thread firmly around the looper thread in the formedstitch without breaking the needle thread. Were this intermittenttension not present the needle thread could not be drawn up tightly bymeans of the vertically adjustable member 88 and the loop 82.

The loop 81 carried by the needle bar lever also serves the purpose ofretaining the thread wit-hin the thread lock. Tere this loop not presentthe tendency of the loop 82 would be to cause the thread to jump out ofthe thread lock due to the rapid up anddown movement of the needle bar.

The loop in the upper end of the needle bar and the verticallyadjustable member carried by the arm 26 act as previously pointed out todraw up the needle thread. This action takes place when the needle hasalmost completed its downward stroke and while the needle thread isunder the additional tension imparted to it by means of the intermittentthread lock, thus taking up the slack while the needle is descending.

The thread tension carried by the needle bar also performs the functionof a thread support for holding the thread and preventing it fromforming a double loop on both sides of the needle. In addition thefunction of the special form of looper thread take-up caml` besidesforming the slack and releasing it, has another drawing-up movement,which acts as a slack take-up for the looper thread and has a tendencyto cause it to lie closely to the fabric, instead of being loose betweenthe stitches of needle thread, and it also holds the looper thread underthis tension long enough to allow the needle thread to be drawn in andthen it is released when the goods are being'fed forward. lVere this notdone the looper thread would not feed with the fabric and would bebroken.

While I have shown an intermittent lock which is operated by camsurfaces working upon each other, still there are various other types ofintermittent lock which may be employed to accomplish my pur ose. Thecssential -feature of the intermittent lock being its location at somepoint between the source of needle thread supply and the needle bar sothat the pulling-up or seating of the thread can be accomplished by theneedle bar, and without putting any addi'- tional tension on the needleduring the pulling-up operation.

Having fully described my invention, what I claim is l. A machine forforming stitches comprising a base having an integrally formed arm, aneedle bar reciprocally mounted in said arm, a needle bar operatinglever pivotally secured to said arm, means for rocking said needle baroperating lever, a needle thread tension mounted on the arm adjacent therear end thereof, an intermittent thread lock carried by the armadjacent the thread tension and operated by the movement of the -ncedlebar operating lever for locking the needle thread at predeterminedintervals, a needle thread pull-up carried by the arm and co-acting withthe needle bar for drawing the loop of needle thread of the previouslyformed stitch taut, a needle thread tension carried by the needle bar, alooper. a quick acting looper thread take-up cam carried by the base ofthe machine, and means for removing the looper thread from the looperthread take-up cam at predetermined positions of the looper.

2. In a machine for forming stitches, a constant tension for the needlethread and looper thread carried thereby, a needle bar lever, a needlebar operated by said lever, a needle thread lock intermittently operatedby said needle bar lever and located adjacent the constant tension, aconstant tension carried by the needle bar, a needle thread pullupcomposed of a stationary member carried by the head of a sewing machineand a member carried by the needle bar and adapted to co-operate withsaid stationary member, a looper, and a looper thread take-up cam fortaking up and releasing slack in the looper thread. i

3. In a machine for forming stitches, a base-having an integrally formeda'rm, con- Stan-t tensions for needle and looper threads carried by saidarm, a needle bar lever pivf otally carried by said arm, a needle barmounted in the arm and operated by said lever, a needle thread lockcarried by the arm and located in front of said constant tensions andadapted to be intermittently operated by the needle bar lever, a guideloop carried by the needle bar lever interposed between the needle barand intermittent thread lock, a constant tension carried by the needlebar, a thread pull-up comprising a stationary member carried by the arm,and a member carried by the needle bar, a looper, and a looper threadtake-u cam for taking up and releasing slack in t e looper thread.

4. In a machine for forming stitches the combination with anintermittently operating needle thread lock, a needle thread pullupabove the lower end of the needle bar,l a needle bar, a needle threadtension carried by the bar, of a looper thread take-up cam adapted totake up and release the slack in the looper thread twice during eachrevolution of the cam and during the action ot' the needle threadpull-up to exert an additional pull-up on the looper thread.

5. In a machine for forming stitches, the combination with a base havingan integrally formed arm, of constant tensions for the needle and looperthreads, a needle bar lever, a needle bar, a needle thread lock carriedby the arm and located to the rear of the needle bar and operated by theneedle bar lever adapted to apply a graduated tension to the needlethread, a guide loop carried by the needle bar lever and interposedbetween the needle bar and thread lock, a constant tension for theneedle thread carried by the needle bar, a needle thread pull-upcoacting with the needle bar, a looper, and a looper thread take-up camadapted to take up and release Slack in the looper thread twice duringeach revolution of the cam one ot' said take-np movements beingaugmented just before the release and during the operations of theneedle thread pull-up whereby the looper thread is caused to lie snuglyalong the underside of the fabric being sewed.

(i. In a mach-ine for forming stitches, constant tensions for theneedleand looper threads, a needle bar lever, a needle bar, anadjustable needle thread lock composed of a stationary cam and a movablecam adapted to be operated by said needle bar lever and located betweenthe needle bar and constant needle thread tension, a guideA loop carriedby the .needle bar lever and interposed between the needle bar andthread lock, a constanttension secured to the needle bar, a needlethread pull-up o erated through the movement of the need e. bar, alooper, a looper thread take-up cam adapted to take up and release slackin the looper thread twice during each revolution of the cam, and meanswhereby said needle bar, looper, and looper thread take-up cam may beplaced in operation simultaneously.

7. In a machine for forming stitches comprising a base having anintegrally formed arm, constant regulated tensions for the needle andlooper threads carried by said arm, a needle bar, a needle carried bysaid bar, a lever for operating said bar, a needle thread lock designedto give a graduated tension carried by the arm and located between theconstant regulated tension and needle bar, means carried by the leverfor intermittently operating said tension, a constant tension carried bythe needle bar, means carried by the arm adjacent the needle bar andco-acting with said needle bar for imparting a retrograde movement to aportion of the needle thread between the intermittent tension andneedle, a looper, a looper thread take-up cam adapted to take up andrelease slack in the looper thread, and means for placing said needlebar, looper and looper thread take-up cam in operation simultaneously.

8. A sewing machine comprising in combination with a base having an armsecured there-to, a needle bar lever pivoted to said arm, a. needle barmounted in said arm, a connection between said needle bar and needle barlever, a looper, meansfor operating said looperlongitudinally,means formoving said looper laterally, a looper take up Cam for taking up andreleasing slack in the looper thread and at predetermined intervals andfor predetermined lengths of time, pan tensions carried by thelarm forengaging the needle and looper threads, a

pan tension carried by the needle bar, an intermittent thread lockcarried by the arm and operated by the needle bar lever, saidintermittent thread lock located between the nee-dle thread pan tensioncarried by the arm and the needle bar, a needle carried by the needlebar, an adjustable 'member carried by the arm adjacent the needle bar, aloop carried by the upper end of the needle bar, said loop adapted topass the adjustable member and act as a pull-up on that branch ot needlethread between the needle andintermittent tension, and means for placingthe needle har operating lever, the looper and looper thread take-up camin operation simultaneously.

9. In a sewing machine, the combination with a base having an arm, aneedle, a needle bar, a needle bar operating' lever, and pan tensionscarried by the arm, Aof an adjustable intermittent thread lock mountedon the arm intermediate the pan tensions and the needle bar and operatedby said needle bar lever, and means carried by the arm and needle barwhereby the downward movement of the needle bar imparts a retrogrademovement of the needle thread through the needle while the intermittenttension is applied, whereby a completed stitch is drawn up and seated.

10. In a sewing machine, the combination with a base having an arm, aneedle bar carried by said arm, a needle carried by said bar, a needlebar operating lever and pan tensions carried by the arm, and a needlethread pull-up, of an adjustable intermittently operating thread lockmounted on the arm intermediate the thread pull-up and the pan tensionsand operated by said needle bar lever for holding the needle threadagainst movement at a predetermined position ot' the needle bar wherebya completed stitch is pulled up and tightlyr seated, and means lorplacing the. machine in operation.

11. In a machine for forming stitches the combination with a sewingmachine head having` van intermittently operated needle thread lock, aneedle and needle bar located in advance thereof, and means forimparting a retrograde movement of the thread through the eye of aneedle during the descent of the needle bar and while the intermittentthread lock is applied, ot a looper and a looper thread cam adapted totake up and release slack in the looper thread twice during itsrotation, said cam being provided with a projection for imparting anadditional pull-up on the looperthread and placing it under tensionwhile vthe needle thread is being pulled up.

12. In a machine for forming stitches the combination with a sewingmachine head having an intermittently operated needle thread lock, meansfor regulating the degree ot tension exerted by said thread lock, aneedle and needle bar located in advance thereof, and means forimparting aV retrograde movement of the thread through the eye ot' aneedle during the descent ol the needle bar and while the intermittentthread lock is applied, of a looper and a looper thread cam adapted totake up and release slack in the looper thread twice during itsrotation, said cam being provided with a projection for imparting anadditional pull-up on the looper thread and placing it under tensionwhile the needle thread is being pulled up.

13. In a machine for forming stitches the combination with a sewingmachine head provided with an intermittently operated needle threadlock, a needle and needle bar located in advance thereof, and adjustablemeans for imparting a predetermined amount of retrograde movement ot thethread through the eye of a needle during the descent ot the needle barand while the intermittent thread lock is applied, o't a looper and alooper thread cam adapted to take up and release slack in the looperthread twice during its rotation, said cam provided with a projectionfor imparting an additional take-up to -the looper thread therebyplacing it under tension while the needle thread is being pulled up.

14. In a machine for forming stitches the combination with a base havingan arm provided with an intermittently operated needle thread lock,means for adjusting said thread lock so as to accommodate various sizesof thread, a needle and needle bar located in advance thereof, andadjustable means for iinpaiting a retrogi'ade movement of the4 threadthrough the eye of a needle during the descent of the needle bar andwhile the intermittent thread lock is applied, of a loop er and a looperthread cam adapted to take up and release slack in the looper threadtwice during its rotation, said cam being provided with a projection forimparting an additional take-up to the looper thread and placing itunder tension while the needle thread is being pulled up whereby thelooper thread is caused to not lie snugly against the work.

.15. In a sewinfr machine, a thread lock, means for operating the threadlock intermittently, means for supplying needle thread under tension tothe thread lock, a needle bar, a needle carried by the bar, means foroperating said needle bar, means co-acting with the needle bar forproducing a retrograde movement of the needle thread through the eye ofthe needle, a looper and looper cam, means for operating the same, meanst'or supplying looper' thread under tension to the looper, said loopercam being arranged to produce and take up slack in the looper threadtwice during each cycle of the needle bar.

16. In a sewing machine, a thread lock, means for operating the threadlock intermittently, means for supplying needle thread under tensiontothe thread lock, a needle bai', a needle cairied by said bar, meansfor operating said needle bar, means col-acting with the needle bar forproducing a retrograde movement of the needle thread through the eye ofthe needle, a looper and looper cani, means for operating the same,means for supplying looper thread under tension to the looper, saidlooper cam being substantially oblong whereby slack is produced andtaken up in theA looper thread twice during each cycle of the needle.

17. In a sewing machine, a thread lock, means for operating said threadlock intermittently, means for supplying needle thread to the threadlock, a needle bar, a needle carried by said bar, and stationary meansco-acting with the needle bar for producing a retrograde movement of theneedle thread through the eye ot the needle.

18. In a sewing machine` a thread lock, means for supplying thread tosaid thread Iock, means for operating said thread lock intermittently, aneedle and needle bar, means for operating said needle bar, and meansco-actlng with the needle'bar during its descent for producing aretrograde movement of the needle thread through the eye of the needlewhereby a. tightly drawn stitch is formed.

19. In a sewing machine, an intermit- 10 tently operated thread lock,means for sup# plying thread to said lock, a needle and needle bar, andmeans whereby the needle bar during predetermined portions of itsmovement will impart a retrograde m0vement t0 the needle thread throughthe eye of the needle and between the needle and the thread lock.

In testimony whereof, I have signed my name to this specification.

DANIEL BELCHER.

